Apparatus for exposing and developing printing plates



Nov. 23, 1965 J. J. LIEDL ETAL 3,218,950

APPARATUS FOR EXPOSING AND DEVELOPING PRINTING PLATES Filed Sept. 4, 1962 9 Sheets-Sheet 1 lll I08 us FIG. IA

INVENTORS JEROME J. LIEDL DONALD L. SNYDER ATTORNEYS Nov. 23, 1965 J. J. LIEDL ETAL 3,218,950

APPARATUS FOR EXPOSING AND DEVELOPING PRINTING PLATES Filed Sept. 4, 1962 9 Sheets-Sheet 2 INVENTORS JEROME J. LIEDL DONALD L. SNYDER ATTORNEYS Nov. 23, 1965 J. J. LIEDL ETAL APPARATUS FOR EXPOSING AND DEVELOPING PRINTING PLATES 9 Sheets-Sheet 3 Filed Sept. 4, 1962 FIG. 2

INVENTORS' JEROME J. LIEDL DONALD L. SNYDER ATTORNEYS Nov. 23, 1965 J. J. LlEDL ETAL 3,218,950

APPARATUS FOR EXPOSING AND DEVELOPING PRINTING PLATES Filed Sept. 4, 1962 9 Sheets-Sheet 4 INVENTORS JEROME J. LIEDL DONALD L. SNYDER wigs/M ATTORNE Nov. 23, 1965 J J. LIEDL ETAL 3, 8,950

APPARATUS FOR EXPOSING AND DEVELOPING PRINTING PLATES Filed Sept. 4, 1962' 9 Sheets-Sheet 5 Isl E I93 g :D' Z 11 INVENTORS' JEROME J. LIEDL DONALD L. SNYDER ATTORNEYS Nov. 23, 1965 J. J. LIEDL ETAL 3,218,950

APPARATUS FOR EXPO-SING AND DEVELOPING PRINTING PLATES Filed Sept. 4, 1962 9 Sheets-Sheet 6 llllhh I A??? INVENTORy JEROME J. uE BY DONALD 1.. SNYDER wwammy ATTORNEYS mmn R E Q 0 RD wmn EW 8 M U Sw M i ED 0 mom N5 T m wm w mmm J m5 RM A :m M 0 Nov. 23, 1965 J. J. LIEDL ETAL APPARATUS FOR EXPOSING AND DEVELOPING PRINTING PLATES Filed Sept. 4, 1962 9 Sheets-Sheet '7 M M WW W an S5 m Nov. 23, 1965 J. J. LlEDL ETAL 3,

APPARATUS FOR EXPOSING AND DEVELOPING PRINTING PLATES Filed Sept. 4, 1962 9 Sheets-Sheet 8 ATTORNEYS Nov. 23, 1965 J. J. LIEDL ETAL 3,218,950

APPARATUS FOR EXPO-SING AND DEVELOPING PRINTING PLATES Filed Sept. 4, 1962 9 Sheets-Sheet 9 INVENTORS 67 JEROME J. LIEDL DONALD L. SNYDER H 364 BY ATTORN United States Patent 3,218,950 APPARATUS FOR EXPOSING AND DEVELOPING PRINTING PLATES Jerome J. Lied], Mahtomedi, and Donald L. Snyder, St.

Paul, lVIinn., assignors to Minnesota Mining and Mannfactoring Company, St. Paul, Minn., a corporation of Delaware Filed Sept. 4, 1962, Ser. No. 221,039 10 Claims. (Cl. 95-775) This invention relates to apparatus for automatically exposing and developing a presensitized plate for use in offset and lithographic printing and more particularly relates to an electromechanical apparatus for preforming successive process steps to prepare the plate for immediate use as a printing plate.

Previously, planograph or lithographic plates formed from a thin metal sheet having at least one surface thereof coated with a light-sensitive organic material, such as a light-sensitive diazo resin, have been exposed by the use of various types of vacuum printing mechanisms. The plates are then removed from said vacuum mechanisms and developed by hand. The development process (where a diazo resin is used as the sensitizer) involves pouring a solution of gum arabic onto the plate and then wiping the same which dissolves and removes the unreacted diazo sensitizer. While the plate is still wet with the gum arabic solution an image developer or strengthener consisting of a resin emulsion is poured on the plate and rubbed in quickly with a soft pad or cotton wad. The excess image developer is then wiped away before it dries completely, leaving a clearly visible image as the particles of the resin adhere to the light struck areas of the diazo resin.

This process for exposing and developing the printing plates requires an excessive amount of time and does not provide consistent results when the plates are developed by hand. A number of the vacuum printing mechanisms employ a light source exterior to the printing mechanism and therefore several minutes are required to expose a plate plus the time required to effect the manual manipulation of the various hoods and to accomplish the vacuum sealing, which brings the negative into close intimate contact with the sensitized surface of the printing plate. After exposure the plates must then be removed and the solutions poured upon the plate and wiped across the surface of the plate to remove the unreacted diazo resin. During this operation a human element enters into the developing process which provides inconsistent results during the processing of several plates. The inconsistent results are due to variances in the amount of solution used in desensitizing the plate, the amount of time used during the wiping operation, or the amount of pressure used in rubbing the plate surface. These variables cause variations in the quality of development in various areas on the plate and development of half tones particularly may be very inconsistent. Additionally, this hand processing requires between 4 to 5 minutes to prepare a plate for the press which in many applications, as in the newspaper industry, is detrimental when time is of the essence. It is therefore necessary to reduce the time required to develop a single printing plate and also to eliminate the inconsistencies resulting from the variables present in the manual processing of the plate. Further, stronger solvents which can produce the best results during processing of the plates cannot be used when the plates are processed by hand but may be used with mechanical processing. This is because the operator will not be subjected to the fumes from such solvents and will not bring his hands in contact with the solvents.

One object of the present invention is to provide an apparatus which will expose and develop a typical inch 3,218,950 Patented Nov. 23, 1965 ice by 15 inch plate at the rate of 6 plates per minute as opposed to the 4 /2 or 5 minutes presently required to perform the same or similar result.

Another object of the present invention is to provide a novel apparatus for exposing a lithographic plate, previously treated with a light-sensitive organic material, through a negative transparency, masked or otherwise placed in composite relation with the said presensitized plate,

Another object of the present invention is to provide a mechanism which will expose and process plates uniformly, by applying the proper amounts of the various processing solutions and providing a uniform amount of scrubbing pressure against the plate during the processing.

Another object of the present invention is to provide novel apparatus which is capable of performing successive developing operations on the exposed plate making the same ready for use on a press.

A still further object of the invention is to provide a unique apparatus which will photographically print a presensitized plate through a negative masked thereto, separate the plate from the negative and develop the latent image on the plate automatically, returning the plate in a dry developed condition for use on a press immediately or at any future time.

A still further object of the invention is to provide novel apparatus of the character above described having a plurality of mechanism arranged along a common path traveled by successive plates for performing successive processing operations on said plate, wherein each mechanism is constructed and mounted as a separate unit to facilitate assembling of the entire machine, as well as to enable unit removal of any mechanism for cleaning, repair or replacement.

A still further object is to provide a novel pressure transport apparatus for advancing flexible sheet material around the surface of a revolvable drum in a manner permitting treatment of said material.

A still further object of the present invention is to provide a novel stacking mechanism for stacking successive plates in a manner to prevent any scraping or scratching of said plates while the same are being stacked.

The above and further objects and novel features of the present invention will fully appear from the following detailed description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended as a definition of the limits of the invention.

In the drawings wherein like reference characters refer to like parts throughout the several views:

FIGURES 1A and 1B constitute an elevation view of an apparatus constructed in accordance with the present invention, certain of the parts being broken away and certain parts located interiorly being shown in phantom lines,

FIGURE 2 is a vertical sectional view taken substantially along the line 22 of FIGURE 3, showing the exposure unit of the apparatus,

FIGURE 3 is an end elevation view of the exposure unit constituting a part of the present invention,

FIGURE 4 is an enlarged elevation view of a coating device which forms a part of the apparatus, certain parts being broken away for purposes of clarity,

FIGURE 5 is an enlarged vertical sectional view taken on line 5-5 of FIGURE 1B,

FIGURE 6 is an enlarged vertical sectional view taken along line 6-6 of FIGURE 1B,

FIGURE 7 is an enlarged elevation view of the stacking device forming a part of the apparatus, certain parts being broken away and certain parts located interiorly being shown in phantom lines,

FIGURE 8 is a detailed sectional view taken along the line 8-8 of FIGURE 7,

FIGURE 9 is an end elevational view of the stacker shown in FIGURE 7, the view being taken generally along the line 9-9 of FIGURE 7, and

FIGURES 10, 11, 12 and 13 are diagrammatic elevation views of the stacking device showing certain parts located in alternative positions during an operating cycle.

Referring now the drawing, there is shown by way of example one form of apparatus constructed in accordance with the present invention. Such apparatus, as will be more readily understood upon consideration of FIG- URES 1A and 1B, includes a work surface or feed platform 20 upon which a presensitized plate member 18 and a negative transparency or printed film member 19, in composite relation with said plate, may be placed for insertion into the apparatus. The composite is shown somewhat exaggerated in the drawing for reasons of clarity. The plate member 18 may take the form of a thin aluminum plate having at least one surface thereof coated with a thin coating of light-sensitive organic material such as water-soluble light-sensitive diazo resin, said diazo resin being characterized in that, upon exposure of the resin coating to actinic radiation, which may in the form of ultraviolet light, through the negative transparency, it will react in the exposed area to become tightly bonded to the plate surface to form an image of water-insoluble, hydrophobic and organophilic material. The negative 19 may constitute a negative transparency taped or otherwise fixed to the plate side of a mask, as is conventional in the printing art, when the size of the transparency is somewhat smaller than the size of the printing plate. This mask, in turn, is then punched to provide a hole or holes on the forward end 19a thereof (as shown somewhat exaggerated in FIGURE 2) over which a pressure-sensitive tape is placed and forced through said hole against the plate 18 forming a composite of the plate and negative and securing the mask in position on said plate preventing relative movement therebetween. The platform 20 is aligned with the entrance area of an exposing mechanism 21 around which the composite is advanced. After being exposed, the composite is directed to a conveying mechanism 22 which provides means for reversing the direction of the composite and places the exposed plate 18 once again on the upper side of the composite with the presensitized exposed surface thereof on the bottom toward the lower part of the apparatus.

The conveying mechanism 22 also directs the composite rearwardly to a separating station, generally designated 23 at which station the members forming the composite are separated. The negative 19 is directed from the separating station to a suitable receptor means or tray 24 and the exposed plate 18 is directed to a receiving and conveying means 25 by which it is carried along a predetermined path to a stacking mechanism 31. Adjacent the path of the conveying means 25 is a coating station 26 which may include one or more coating mecha nisms; a scrubbing station 27; a cleaning or rinsing and wiping station 28; a second coating station 29 and a drying station 30. At the end of the predetermined path the plate is fed into the stacking mechanism 31 which stacks the developed plate 18' in a suitable receptor means such as the bed or tray 32.

Turning now to a detailed description of the disclosed apparatus constructed in accordance with the present invention, such apparatus has a primary vertically positioned supporting plate 33 extending longitudinally through the machine which serves to support the various mechanisms in a cantilever manner as will hereinafter appear. The plate or wall 33 serves to separate the various mechanisms, disposed on one side thereof, from the driving mechanism and electrical circuitry disposed on the opposite side in a manner providing convenience of operation and maintenance. The apparatus is also provided with a base member 34 and a plurality of enclosing top, side and end panel sections (not shown) which serve to enclose the machine. Positioned on the forward side of the machine is the work surface 20 which is in aligned relation with the entrance area of the exposing mechanism 21 and said surface is supported between upright, more decorative, side panels 20a, only one of which is shown in the drawing.

The exposing unit 21 shown most clearly in FIGURES 2 and 3 is an integral unit independently supported on the wall 33 and comprises a frame portion formed of a pair of upright J-shaped transversely spaced apart plate members 35 and 36 which are supported in said spaced relation by a transversely extending vertically disposed plate 37 fixed to said members 35 and 36 by suitable fastening means such as bolts 37a. The frame is supported from the wall 33 by a plurality of spacers 38 connected at the ends thereof to the plate 35 and wall 33 by bolts 39. The frame further comprises a pair of smaller vertical plate members 40 and 41 which may be pivoted intermediate the ends thereof with respect to the plates 35 and 36. Plates 35 and 36 and plates 40 and 41 are formed with aligned bearing openings journalling a transverse shaft 42 about which plates 40 and 41 may pivot. One end of the plates 40 and 41 is provide with an opening 43 which may be aligned with matching openings 44 or 45 formed in each of the plates 35 and 36. When the unit is placed in operative position, the openings 43 are aligned with the openings 44 and a rod 46 having a hand grip portion 47 is inserted through the openings 44 and 43 and is threadably retained therein by means of threads provided in the opening 44 formed in plate 36 and matching threads formed on the end of said rod (see FIGURE 3). To pivot the plates 40 and 41 upward the rod 46 is removed, the plates are pivoted and the rod is inserted through the openings 45 and 43 to retain the plates in raised position.

Mounted on the frame for rotation on parallel axes in the spatial relationship shown, are a printing roll in the form of cylinder 48, a feed or drive roll 49, a discharge roll 50, a tensioning idler roll 51 and three idler rolls 52, 53 and 54, the roll 54 being supported on the shaft 42. Traversing the rolls 48 through 54 is a narrow flexible endless belt 55 which makes successive wraps therearound in a manner to be hereinafter described.

The drive roll 49 and tensioning roll 51 are mounted on shafts 49a and 51a each of which are journalled at the ends thereof in adjustable bearing blocks 56 and 57, respectively. The blocks 56 and 57 are vertically adjustable in slots 58 and 59, respectively, formed in the plate members 40 and 41, as shown in FIGURE 2, and suitable adjustable bolt members 60 and 61 are provided to adjust said blocks 56 and 57 within said slots and retain the same in adjusted position. The bolt members 60 and 61 are threaded through bars 62 and 63 which are fastened across the open ends of the slots 58 and 59. The bolt members 66 and 61 are retained in adjusted position by the use of lock nuts 64 and 65. The shaft 4% extends axially through the bearing block 56, carried by plate 40, and has a gear wheel 66 secured on the end thereof to drive the feed roll in the direction of the arrow 4%. The gear wheel 66 is substantially the same diameter as roll 49 and intermeshes with a gear wheel 67 carried on a stub shaft 68. The stub shaft 68 is bearinged in a sleeve 69 and projects through the support wall 33. The projected end of stub shaft 68 has a sprocket wheel 70 fixed thereto around which is passed a drive chain (not shown) driven by suitable means such as an electric motor (not shown).

The discharge roll 50 is fixed to a shaft 50a which is journalled in the plate members 35 and 36. This roll 50 is positioned below and forward of the drive roll 49. The idler roll 52 is mounted on a shaft 52a journalled in the plate members 35 and 36 and is positioned below and rearward of the drive roll 49, as shown in FIGURE 2.

The printing roll 48 takes the form of a cylindrical sleeve of glass or other radiant energy transmissive material and the mounting for said roll is of the floating type. The roll 48 is cradled above and between the discharge roll 50 and the idler roll 52 and is held in this position by the drive roll 49 when in the operative position as shown in the drawing. Axial displacement of the printing roll 48 is prevented by a pair of following rollers 71 and 72 which are journalled on suitable rods or shafts 73 (only one of which is shown in FIGURE 2) fixed to the pivotal plates 40 and 41. Upon pivoting the plates 40 and 41 upwardly, as previously described, the cylinder or roll 48 is easily accessible.

The idler roller 53 is mounted on a shaft 5311, which is journalled in the plates 35 and 36, and is positioned below the transverse support plate 37. The idler roller 54, mounted on the shaft 42, is positioned vertically above said plate 37, as shown. The rollers 53 and 54 are so positioned that a plane tangential to the belt-directing faces of said rollers along the rearward peripheral surface thereof is parallel to the plane of the plate 37.

The flexible endless belt 55 makes successive wraps around the rolls 48 through 54 and may be formed of an inert polymeric material such as polytetrafiuoroethylene providing a translucent or transparent belt or, as in the illustrated apparatus, may be formed of a laminate consisting of a nylon backing 55a faced with a foam rubber 5511 having voids therein making the material compressible but not deformable. The belt is narrow in width and suitable steering means are provided such that the belt makes several advancing cycles around the roll 48 forming simultaneous side-by-side convolutions therearound to cover a major portion of the length thereof.

Referring particularly to FIGURE 3, a first set of steering rollers 74, rotatably mounted on stub shafts 75 and retained thereon by snap rings, are shown positioned in a row along the center portion of support plate 37. Vertically above the rollers 74 is a second row of rollers 77, mounted on shafts 78 and retained by snap rings, positioned along the upper transverse edge of the plate 37 and parallel with the row of rollers 74. Each roller 77 of the second row is offset to the left, as shown in the drawing, of the corresponding roller 74 in the lower row. The two rows of rollers are positioned, with respect to the transverse rolls 48 through 54, to guide the simultaneous convolutions of the belt 55 around the printing roll 48 in side-by-side relation with each -convolu tion of said belt following a path on the periphery of the printing roll 48 formed by two parallel planes perpendicular to the axis of said printing roll 48. Or in other words a point on belt 55 as it advances around the roll 48 remains in a plane perpendicular to the axis of said roll.

Means including a pair of pulleys 88 and 83 and a pair of steering rolls 81 and 82 provide a return cycle to move the belt 55 from one end of the printing roll 48 across to the opposite end thereof, returning the belt to a position where a given point on said belt begins to make the successive advancing cycles. The pulleys 80 and 83 and rolls 81 and 82 are suitably mounted on the vertical plates 35 and 36, rearward of the plate 37. As the belt comes oif the idler roll 53 (see FIGURE 2) adjacent the outer end of the copy roll 48, it is directed around the end of roller 53 and around the pulley 80 and is moving in the direction of arrow 84 (see FIGURE 3). The belt is then turned or twisted 90 degrees to the left and directed upward over the roll 81 and then downward across the frame to the roll 82. The rolls 81 and 82 are mounted for rotation on axes which are essentially perpendicular to the axes of the rolls 48 through 54 and the pulleys 80 and 83. After passing around roll 82, the belt is twisted 90 degrees to the right and is directed upward around pulley 83, which is rotatable on an axis parallel with rolls 48 through 54, and then is directed in an advancing cycle around idler roll 54, tensioning roll 51, to the belt-reversing face of the drive roll 49, the surface of the printing roll 48, the belt-reversing face of the discharge roll 50, and the belt-directing face of the roll 53. Upon making this portion of an advancing cycle the belt is turned degrees to the right and the back side of the belt engages one of the steering rollers 74, then the belt is directed upwardly and to the left (see FIGURE 3) and the rubberfaced side of the belt engages one of the steering rollers 77. The belt is then turned back to the left 90 degrees and directed around the belt-directing face of roll 54 to make another cycle around said rolls and the printing roll 48 forming side-by-side convolutions. The foam rubber surface of the belt engages the printing roll 48 causing said roll and belt to convolve around the axis of said roll in the direction indicated by the arrow 48a.

The above described belt and steering means therefor, provide a system which may be employed to provide exposure units having various widths and has the further advantage of providing longer belt life on a unit. The latter advantage arises from the fact that, in prior machines employing a single belt around the printing roll or a plurality of narrow belts, the center portion of the belt or the center belts receive all the wear and become distended. In the present pressure transport system the wear is equalized over the entire belt surface providing uniform operating characteristics for the life of the belt.

The adjustment provided for the drive roll 49 allows adjustment of the compressive pressure placed on the belt 55 in the nip area between said drive roll and the printing roll 48. As the composite formed of the presensitized printing plate 18 and the negative 19 is fed into the exposing mechanism 21, they are squeezed together and compressed between the belt 55 and the printing roll 48 in the nip area beneath the drive roll 49 forming the entrance into the exposure or treatment zone around said roll 48. The squeezing of the composite at the nip area forces out any air that might be trapped between the plate 18 and negative 19, thus placing them in intimate contact with the printing roll 48 and with each other. The composite is then advanced around the printing roll 48 by the belt 55, past an elongated light source, shown as a gas-filled lamp 86 positioned within said printing roll, which provides an abundance of actinic radiation in the form of ultraviolet light to expose the plate 18 through the negative 19. The lamp 86 is supported at each end in suitable mounting brackets 87 and 88 which fit over conventional insulating caps 86:: and 86b on the ends of the lamp. The mounting bracket 87 comprises an upper and lower plate portion, 87a and 871) respectively which have been cut and bent from the outer end of a flanged sleeve 89 formed of sheet metal. The sleeve 89 is in turn secured by its flanged portion 8% to the support wall 33 by screws or bolts 90 and is positioned concentrically with an opening 91 formed in said wall 33. On the opposite side of the wall 33 and mounted over the opening 91 is a housing 92 encasing the discharge side of a blower or fan (not shown) which directs air through the copy roll 48 to cool the lamp 86.

The bracket 88, supporting the outer end of the lamp 86, comprises a pair of bent portions which fit about the insulating cap 86b. The bent portions of the bracket 88 are formed integrally with a thin vertically extending sheet metal plate member 93 (see FIGURES 1 and 3) secured at its lower end by suitable fasteners 93a to the plate 36.

Positioned within the copy roll 48 and extending therethrough is a shield 94. This shield 94 is mounted at its outer end on the plate member 93 and is supported at the inner end on the sleeve 89 by a bracket 95. The shield 94, as shown, is positioned substantially in a diametric position with relation to the printing roll 48 and is positioned forward of the lamp 86 thus providing an enlarged exposure area through which the printing plate and negative traverse to expose the same and impart a latent image onto said plate.

After the composite has traversed the exposing area, said composite is directed across a shelf 96, see FIGURE 1A, into the conveying mechanism 22. The conveying mechanism 22 serves both to reverse the direction of the composite and to convey it in a rearward direction to the separating station 23. The conveying mechanism 22 comprises a driven rotary drum 97 fixed to a shaft 97a bearinged in a pair of vertically disposed transversely spaced plates 98, only one of which is shown in FIGURE 1A. Disposed around the peripheral surface of said drum 97 are three a-djustably mounted idler rollers 99, 100 and 101, rotatably supported by the vertical plates 93, around which traverses an endless web or belt 110. Belt 1110 extends substantially the full length of the drum 97 and is placed in driving engagement therewith by the idler rollers. The drum 97 is driven from the shaft 97a which extends through the wall 33 and has a sprocket (not shown) keyed on the extended end portion. The sprocket is driven by a main drive chain powered from a suitable motor and variable drive gear box (not shown) located on the opposite side of the wall 33. The plates 98 are supported by a cantilever frame 102 comprising a shelf portion 103, vertically disposed plate portion 104 and brace members or gusset plates 105 and 106. The frame 102 is fixed to the vertical wall 33 by suitable fastening means such as bolts 107 extending through the plate portion 104 into said wall. Frame 102 additionally supports a pair of upright parallel transversely spaced plate members 108 on the right hand side thereof as shown in FIGURE 1. The plate members 108 provide support for bearings journalling an adjustably steering roller 109 around which the belt 110 is also passed, thus providing a suitable conveyor in conjunction with the drum 97 to carry the composite to the separating station 23.

The separating station 23 comprises a pair of rubberfaced squeeze rolls 111 and 112 mounted on driven shafts 113 and 114 respectively, bearinged in the aforementioned plates 108. The shaft 114 extends through the wall 33 and carries a sprocket (not shown) on the extended end thereof, driven by the main drive chain. A gear Wheel (not shown) is keyed to each of the shafts 113 and 114, adjacent the inner plate 108, and are intermeshed to drive said shafts at the same speed. The roll 112 has a diameter, however, greater than the roll 111, which is positioned vertically above and spaced from said roll 112 a distance somewhat less than the combined thickness of the composite formed by the negative 19 and plate 18. With the pair of rolls driven at the same speed, but having different diameters, they have different surface speeds at the nip area therebetween which results in relative movement between the negative and the plate as they move between said rolls. This relative movement results in snapping the holding power of the tape by which the masked negative is secured to the plate thus allowing separation thereof. The differential speed also causes the negative, engaged by the roller 112, to be carried through the separation area 23 in advance of the plate 18. As the negative is carried rearwardly, it engages a driven couch roll 115 positioned rearwardly and beneath a suitably supported shelf 116. The couch roll 115 is driven by a shaft 115a in the direction of arrow 117 and is provided with openings (not shown) on the peripheral surface thereof. The roll 115 is connected to a suitable vacuum source and serves to draw the rearwardly moving negative therearound, directing the leading end of the same downwardly into engagernent with a stationary deflector member 118. As the negative engages the deflector, it is directed downward thereby and is received and stacked in the tray 24.

As the exposed plate 18 is carried rearwardly through the separating rollers 112 and 113, it is picked up by the conveying means 25. The conveying means 25 comprises an endless Fourdrinier paper mill screen web 120 which traverses an idler drum 121, a rotatably driven drum 122 and a steering drum 123. Idler drum 121 is supported on the shaft 121a journalled in a suitably cantilevered moves the unreacted diazo sensitizer.

support frame 124. Driven roll 122 is supported on a suitable shaft 122a journalled in a support frame 125. Frame 125 is positioned substantially parallel with respect to the frame 124 and is disposed toward the rear of the machine as shown in FIGURE 1B, thus defining a substantially straight line run or stretch for the screen 120 between the drums 121 and 122. The shaft 122a projects through support wall 33 and is driven from the main drive chain by means such as a sprocket wheel (not shown) keyed to said shaft. The steering drum 123 is disposed vertically above the idler drum 121 and is supported on a shaft 12311. The shaft 123a is journalled at the ends thereof in a pivoted yoke member 126. The yoke 126 is provided with a shaft member 129 extending perpendicularly from the bight portion of the yoke and is pivotally received in a frame member 123 mounted in a cantilevered manner from the support wall 33. The screen 120 passed around the drums 121, 122 and 123 and defines the predetermined path along which the exposed plate 18 is conveyed.

Positioned above the screen 120 in the straight-line stretch of said screen between the idler drum 121 and the driven drum 122 are a series of suction boxes 130, 131, 132 and 133. These suction boxes are connected by suitable conduits 130a, 131a, and 132a and 133:: to a suitable pump or other means which will create a subatmospheric pressure within said boxes. The subatmospheric pressure within the boxes 130 through 133 will draw the plate 18 against the surface of the Fourdrinier screen 120 and will hold the plate on said screen such that it is carried by the screen along the straight line stretch.

As the plate 18 is carried along the predetermined path by the screen 120, it is carried through a series of stations which develop the latent image produced on the plate in the exposure mechanism. The first station which the plate enters along this path is the coating station 26 adjacent the straight-line stretch of the screen 120. At this station the exposed surface of the plate is coated uniformly with a solution of gum arabic, which dissolves and re- While the plate is still wet with the gum arabic solution, an image developer comprising a resin emulsion is coated on the same exposed surface. The image developer is not necessary insofar as an operative printing plate is concerned, but is of practical importance in aiding the lithographer or printer to determine whether he is placing the plate on the press correctly and this can be done only if a visible image is present or by time consuming trial and error.

As the plate enters the coating station 26, a photoelectric cell 135 detects the presence of the moving plate and actuates a suitable timing device which in turn actuates a first coating assembly 136 moving it to an operative position, wherein said assembly 136 applies the desensitizing solution to the plate as it is moved along said path. After coating the exposed surface, the timing device is operative to move the coating mechanism to an inoperative position, withdrawn from the surface of the plate. As the plate continues along said path past the coating mechanism 136, its presence is detected by a second photoelectric cell 137. This photo cell 137 operates a second electrical timing device causing movement of a second coating mechanism 138 from its inoperative position to its operative coating position. The coating mechanism 138 is operative to apply a coating of image developer onto the exposed surface of the plate 18, while the plate is still Wet with the first process solution, and is then returned to an inoperative position.

The coating mechanisms 136 and 138 are supported by a pair of longitudinally extending tubular bars 139 and 140 which are mounted in parallel vertically spaced relationship, as shown on the drawing, to the main support wall 33 by brackets 141. The bars 139 and 140 permit the coating mechanisms 136 and 138 to be moved toward and away from one another thereby changing the spacing between said mechanisms.

The coating mechanisms 136 and 138 are similar in construction, the mechanism 136 having the upper portion thereof reversed with respect to the mechanism 138 as will be described in greater detail hereinafter. Referring now to FIGURE 4, the coating mechanism 138 comprises an upper frame 142 and a lower frame 143. Frame 143 comprises a pair of vertical transversely extending plate members 144 and 145 which are adjustably supported, by suitable U-shaped clamps (not shown) fixed to the inner ends thereof, on the longitudinal bars 139 and 140. Extending between the plate members 144 and 145 are a plurality of transversely spaced plate members. The transverse plate members comprise three similar U-shaped upper plates 146, 147 and 148 spaced between the inner and outer ends of members 144 and 145 and a rectangular plate 148 positioned between the lower edges of said members. The plates 146, 147 and 148 support transversely extending angle bars 150 and 151 which are positioned also along the upper edges of members 144 and 145. Bars 150 and 151 form a channel shaped mounting surface in which the upper frame 142 is fitted.

The upper frame 142 comprises a pair of transversely extending angled bars 152 and 153 which slide between the vertical flanges of the angle bars 150 and 151. The bars 152 and 153 have fixed thereto a pair of vertical end plates 154 and 155. A substantially cylindrical member 156, having a longitudinal section removed, is positioned between and fixed to the end plates 154 and 155. The cylindrical member 156 forms a reservoir between the end plates 154 and 155. An inlet port 156a is formed in the lOWer surface of the cylinder 156 through which a solution 180 may be pumped by suitable means from a storage supply. One longitudinal edge of the member 156 defines the top of the reservoir and any solution spilling thereover is collected in a trough formed by a plate 156b and the member 156 as shown. This retained solution can then drain through an opening a formed in end plate 155 back to the supply.

A fountain roller 157 is positioned within the reservoir formed by member 156 and is secured to a shaft 158. The shaft 158 is journalled at each end thereof in eccentric bushings 159 which extend through flanged openings formed in the respective end plates 154 and 155. Rotatably mounted on the flanges forming the openings for the eccentric bushings 159 and exteriorly of the end plates 154 and 155 are a pair of rockable crank arms 160, only one of which is shown. The arms 160 are provided at the upper end thereof with slotted openings 161 which receive therein bushings 162 adapted to journal a shaft 163. Shaft 163 supports and has secured thereto a coating roller 164. The bushings 162 are held in the slotted openings 161 by means of retaining pins 165. The arms 160 also support a suitable transversely extending scraper 166 which is adjustably mounted adjacent to the roller 164.

The depending portion of the arms 160 extend downwardly, from the flanged openings in the plates 154 and 155, between brackets 169 which has threaded therein adjustable set screws 170 and 171 defining the limits of rocking movement to which the arms 160 may be subjected. The depending portion of the arms 160 support a transverse sleeve 167 mounted on concentric stub shafts 168, only one of which is shown, journalled in said depending arm portions. As shown in FIGURE 4 the arms 161) have been rocked in a clockwise direction to the limit defined by the adjacent set screw 170. In this position the arms 160 pivot the coating roller 164 upward about the axis of the openings formed in the end plates 154 and 155 and into coating position with respect to the moving exposed plate 18.

The shafts 158 and 163 carrying the fountain roller 157 and the coating roller 164, respectively, are provided with key ways 158a and 163a adjacent each end thereof.

These key ways provide means for mounting intermeshing gear wheels on either end of the shafts. The gears (not shown) which drive the shafts 158 and 163 are secured to the inner ends of the shafts and are intermeshed for uniform rotation of said shafts. The gear mounted on shaft 158 is formed with a hub which fits with a corresponding hub carried by a stub shaft (not shown) extending through the support wall 33 and driven by the main drive chain. The hubs are constructed to form a bayonet clutch thus continuously driving the shafts 158 and 163 from the stub shaft and driving the fountain roller 157 in a clockwise direction indicated by the arrow 173, and driving the coating roller 164 in a counterclockwise direction.

Mounted exteriorly of the arms 160 and clamped to each of the eccentrics 159 are arcuate disk members 174. The disk members 174 have teeth formed on the arcuate edges engaging teeth formed on the periphery of a pair of wheels 175 which are fixed on opposite ends of a transverse rod 176. Rod 176 is rotatably mounted in the end plates 154 and 155 and suitable locking means, comprising a plate member 177 and a bolt 178, frictionally lock the wheel 175 and rod 176 in any desired adjusted position. Rotation of the rod 176 and wheels 175 rotate the disks 174 and the eccentric bushings 159 thus adjusting the position of the axis of fountain roller 157 with respect to the axis of the coating roller 164. This adjustment provides means by which the amount of solution 1180 applied to the coating roller 164 and thus to the surface of the plate 18 may be varied to give the desired amount of coating solution on said plate.

The rockable arms 160 are shifted from the operaative coating position shown, to an inoperative position, and vice versa, by a pair of rockable links 181, only one of which is shown in FIGURE 4. The links 181 are disposed one on each side of the center plate 147 of the lower frame 143. The upper ends of the links 181 are bifurcated to fit around the sleeve 167 journalled on the arms 160. The links 181 are rocked or pivoted about a pin 182 which extends through the plate 147 and through suitable openings formed in said links intermediate the ends thereof. The lower ends of the links 181 are connected by means of a pin 183 to a reciprocating connecting rod 184 which is driven by a diaphragm-type fluid motor 185. The connecting rod 184 is slidably supported at one end by a sleeve 186 fixed to the plate memher 144 and is slidably supported adjacent its other end in a suitably sealed bushing 187 fixed in the center of a circular drum 188 forming part of the chamber of the motor 185. A drum 189 forms the other half of the motor chamber and the two drums are suitably secured together, with a diaphragm 1911 held in position therebetween, by spaced fastening means in the form of bolts 191. Suitable intake and exhaust ports 192 and 193 are formed in the drums 188 and 189 and have secured therein, by means of threads, suitable fluid conduits 194 and 195. The conduits 194 and 195 are connected at their other ends to a suitable four-way valve (not shown) operated by the timing device. The valve in turn is suitably connected to a source of fluid under pressure which will operate the motor 185.

Retaining means is provided to retain the upper frame 142 in position on the lower frame 143. The retaining means comprises a pair of rods 197, only one of which is shown in FIGURE 4, extending through the plate members 144 and 145. The rods 197 are journalled, adjacent the ends thereof, in blocks 198 secured to the members 144 and 145. The blocks 198 are formed with a vertical groove on their outer side to fit around and slidably receive the lower portion of vertically positioned hooks 199. The hooks 199 are provided with openings in the lower portions which receive therethrough eccentrics 200 of reduced diameter formed in the ends of the rods 197 which, upon rotation of the rods, impart vertical movement to the hooks 199. The rods 197 have a radially extending crank arm 201 fitted in one end thereof providing means for manually rotating the rods 197 causing the hooks 199 to move into and out of clamping engagement at their upper ends with the transversely extending angle bars 152 and 153 of the upper frame 142. This clamping arrangement between the upper frame 142 and the lower frame 143 of the coating mechanism 138 provides an easy means for removing the upper frame from the machine for purposes of cleaning and as aforementioned the upper frame may be reversed with respect to the lower frame. To reverse the upper frame the gears keyed to the roller shafts 158 and 163 are merely moved to the opposite ends of said shafts and the frame 142 is rotated 180 and returned to its position on the transverse angle bars 150 and 151 of the lower frame 143. This reversal causes the coating roller to rotate clockwise about its axis thus the peripheral coating surface is moving in the same direction as the plate 18.

The coating mechanism 136 is reversed with respect to the coating mechanism 138 and applies the solution from the reservoir thereof to the plate 18 with a rolling action. The coating roller 164 of the mechanism 138 is rotated in a counterclockwise direction reverse to the direction of the plate 18 thus applying the solution 180 to said plate with a reverse action, covering the coating applied by the mechanism 136.

The coating mechanisms 136 and 138 are also adjustable along the longitudinal bars 139 and 140 relative to the scrubbing station 27 to insure that the plate arrives at the scrubbing station with the coatings still wet. This adjustment for a series of plates will then provide constant predetermined time interval between processes. At the scrubbing station 27 the coatings are rubbed into the exposed presensitized surface of the plate 18 to dissolve the unreacted diazo sensitizer and cause particles of the resin emulsion to adhere to the image areas.

The scrubbing station 27 is located beneath the vacuum box 132 which is formed, as shown in FIGURE 1B, with a convex lower portion for a reason to be described as this description proceeds.

The scrubbing station 27 comprises means for effectively working the entire coated plate surface and includes a scrubbing belt 203 which is reversely driven with respect to the direction of the screen web 120 and at the same time is reciprocated with respect to the support wall 33, imparting bidirectional movement to the belt 203 with respect to the screen web 120. The belt 203 is drivingly supported by three drums 204, 205 and 206 mounted in a triangular fashion as shown in FIGURE 1B. The drums 204, 205 and 206 are suitably carried on shafts 207, 208 and 209 respectively, supported by a main support or spider 210.

Referring more particularly to FIGURES 1B, 5 and 6, the spider 210 comprises an inner plate 211 and an outer plate 212 formed with projecting spokes or arm portions 204a, 205a and 206a. The plates are fixed at their centers to opposite ends of a cylindrical hub 213 by means of suitable fastening bolts 214 extending through the plates and threaded into flanges 215 and 216 fixed to the hub 213 as by welding. The hub 213 is slidably mounted on a cantilevered shaft 217 fixedly mounted by means of a sleeve 218, flange 219, bolts 220 and nuts 221 to the support wall 33. The shaft 217 projects through an opening 222 formed in the spider plate 211 and extends concentrically into the hub 213. Bearing sleeves 223 and 224, formed of bronze or other suitable material, fitted in the hub 213 provide for axial sliding between said hub and the shaft 217.

Th drum 204 is a flanged drum and is rotatably mounted by means of bearings 225 and 226 on the shaft 207. The shaft 207 is keyed at each of its ends in eccentric bushings 227 and 228 fitted in the arms 204a of the plates 211 and 212. The eccentric bushings 227 and 228 allow adjustment of the axis of the drum 204 with respect to the axes of the support shaft 217, fa-

cilitating the mounting of the belt 203 around the drums and tightening the belt to the desired degree after mounting.

The drum 205 serves to drive the belt 203 and is fixed to the driven shaft 208 as by set screw 230. The driven shaft 208 is journalled in the arms 205a of the plates 211 and 212, by means of suitable bearings 231, 232 and 233, and extends through the support wall 33. The shaft 208 is journalled in the support Wall 33 by means of a suitable bearing 234. A sprocket wheel 235 is slida'bly mounted on the extended end of the shaft 208 by a key 208a fitted in said wheel and in said shaft. The wheel 235 is positioned on said shaft between the support wall 33 and a fixed bracket 237 formed with an opening 236 through which the shaft 208 extends. A spacer or washer 238 and a sleeve 239 retain the sprocket wheel 235 in position between the wall and the bracket 237 but allow axial movement of the shaft 208. The main drive chain passes around the sprocket wheel 235 thus driving the sprocket wheel 235, shaft 208 and drum 205 in a counterclockwise direction as viewed in FIGURE 13.

The drum 206 is rotatably mounted on the shaft 209 which is fixed at its ends in the arms 206a of plates 211 and 212 forming the spider 210. The arms 206:: are formed with suitable clamps, shown in FIGURE IE to secure the shaft 209 therein.

Axial movement or reciprocal movement of the spider 210 with respect to the screen web and wall 33 is provided by means of an independent drive from the main drive chain through an electrically actuated clutch and a pitman connection with said spider. Referring particularly to FIGURES 1B and 6, a projection 241, formed on the plate 211 between the arms 205a and 206a, receives therein one end of a transverse rod 242. The rod 242 is adjusta-bly fixed to the rejection 241 by means of lock nuts 243 and 244 and is formed with an eye on the other end which receives a pin 245 therethrough. The pin 245 is journalled in the yoke end of a pitrnan 246 formed with an opening 246a in the opposite end thereof. An eccentric collar 247 keyed to a shaft 248 provides the drive for the pitman 246 thus imparting reciprocation to the rod 242 and spider 210. The shaft 248 is drivingly connected by an electrically operated clutch mechanism (not shown) to the main drive chain. The clutch mechanism is operated by the timing device electrically connected to the photoelectric cell 137. The timing device actuates the clutch in timed relation with the speed of the web 120 such that the belt 203 and spider 210 are reciprocated only when a plate 18 is moving through the scrubbing station 27. The reciprocation of the spider 210 on the shaft 217 imparts reciprocation to the belt 203 and when combined with the drive of the belt around the drums 204, 205 and 206 a bidirectional movement for the belt 203 is provided with respect to the screen web 120 and the plate 18 carried thereby.

The belt 203 is wider than the plate 18 and is formed of a backing on which has been coated a combination of fibers to form a pile type scrubbing surface. The belt 203 is constantly cleaned during operation to maintain a continuous effecitve scrubbing action. The cleaning of the pile is accomplished by a rotatably mounted broom or brush unit 243 (see FIGURE 1B) carried on a shaft 250 which is driven by the main drive chain. The brush unit 249 is housed within a hood 251 positioned adjacent to the moving belt 203. The hood is connected by means of a tube 252 to a pump or blower (not shown) creating a sub-atmospheric pressure within the housing 251 thus making the brush unit and hood operate in a manner well known in vacuum sweepers.

The belt 203 is also subjected to a water spray which aids in washing the processing solutions from the pile of said belt and dampens the belt to aid in the scrubbing action. The spray is discharged from a series of nozzles or orifices formed in one side of a transversely extending tube 254 suitably connected, as by a conduit 255, to a supply of water under pressure.

The vacuum box 132 is convexly shaped along the lower edge thereof to deflect the screen web 120 downward toward the belt 203. With the belt 203 moving in the direction of the arrow 256 and reciprocating with the spider 210, constant engagement between the belt and web is effected and as the plate 18 is carried along said web, a constant pressure is maintained between said belt and said plate. This pressure and bidirectional movement of the belt ensures uniform treatment of every square inch of the plate.

The next station to which the plate 18 is moved along the path of the screen web 120 is the cleaning or rinsing and wiping station 28. As the plate is carried along the web, a spray of water discharged from a series of orifices in a transversely extending pipe 257 impinges on the surface of said plate to wash away the desensitizing solution and surplus of developer remaining on the plate surface. After the washing a transversely extending squeegee 259, formed of a strip of rubber mounted on a suitable holder, wipes the surface of the plate thus wiping off the water and solvents or processing chemicals.

Below the coating station 26, the scrubbing station 27 and the rinsing and wiping station 28 a sloping tray 260 is provided which slopes downwardly and rearwardly of the machine to a drain tube 261. The tube 261 is preferably positioned over a floor drain in the area in which the machine is operating. A second plate member 262 operates to aid in deflecting the water from the rinsing station 28 into the drain. An opening 262a is formed in plate 262 adjacent the drain 261 and is covered by a filter 263.

A conduit 264 is suitably fixed at one end over said opening 262a and is connected at the opposite end thereof with the intake side of a blower 265. The blower 265 provides means for drawing the odorous vapors through the filter and circulating the air within the enclosed apparatus.

After the plate 18 passes beyond the rinsing and wiping station 28, it is carried around the drum 122. A flexible conveying belt 266 which passes around a steering roller 267 and a pair of idler rollers 268 and 269 supports the plate on the web 120 and carries the same around the drum 122. The rollers 267, 268 and 269 are suitably journalled in a pair of upright plate members 270, only one of which is shown in FIGURE 1B mounted in transversely spaced relation on an angle member 271, one flange of which extends horizontally outwardly from the support wall 33 and the other flange is flush with said wall and secured thereto by suitable fasteners 271a.

After passing around the drum 122, plate 18 is now carried on the upper side of the web 120 to the coating station 29. As the plate approaches the coating station 29, its presence is detected by a photoelectric cell 273. The photoelectric cell is suitably connected with a timing device to actuate a solenoid which in turn moves a compression roller 274 of the coating mechanism upwardly. The compression roller 274 is journalled at each of its ends in an arm of a pair of bell-crank levers 275 which are pivotally mounted intermediate their ends to a pair of transversely spaced support plates 276. Connected to the other arms of the bell-crank levers 275 are adjustable connecting links 277. The links 277 are pivotally connected to the bell-crank levers at one end and are pivotally connected at their other ends to radial arms 278 which are fixed to a shaft 279 rotatably mounted in the plates 276. The shaft 279 is suitably connected to a solenoid (not shown) to effect oscillation of said shaft 279 upon actuation of said solenoid by a timer and the photoelectric cell 273. As the roller 274 is moved upwardly, it forces the web 120 and the plate 18 upwardly into coating position with a coating roller 280. The coating roller 280 is wetted by a moistening roll 281, ductor roll 282 and a fountain roll 283. The fountain roll is positioned within a tray 284 containing a supply of a processing solution such as arabic gum. The rolls 280, 281, 282 and 283 are journalled in a frame formed by a support plate 285 fastened to the support wall 33 and by a plate 286 secured to and depending from a rod 287 projecting in a cantilever manner from said plate 285. The rolls 280-283 are suitably driven by intermeshing gears carried on the inboard end of each of said rolls and are suitably driven from the main drive chain. The compression roll 274 is driven by its engagement with the moving wire screen web 120.

As the plate 18 passes through the coating station 29, a film of arabic gum is coated over the image on the plate 18 to form a cap over the image which is watersoluble but which gives a mechanical protection to the image until such itme as the plate is to be used on a press. This coating is dried on the plate surface as the plate is carried through the drying station 30.

The drying station 30 comprises a pair of hoods 289 and 290 secured to the support wall 33 by any suitable means. The hoods 289 and 290 are similar in structural configuration and are disposed on opposite sides of the web along the straight stretch thereof between drum 122 and drum 123. The hoods serve to direct forced hot air toward the web 120 and the plate 18 as they pass therebetween. The air is forced by a blower 292 into a plenum 293. Positioned within the plenum 293 is an electrical heating unit 294 in the form of a grid which serves to heat the air as it is forced therethrough into a pair of ducts 295 and 296 which carry the air to the respective hoods 289 and 290.

As the plate comes out of the drying station 30, it is carried under a floating roller 298, positioned at the end of the path described for said plate by the web 120, which directs the plate into the stacker 31. Roller 298 is journalled at its ends in a pair of yoke members 299 extending vertically upward and supported from the yoke 126.

As the plate 18 passes between the roller 298 and the drum 123, it is directed in a horizontal path across a shelf 301. As the plate crosses the shelf 301, its presence is detected by a photoelectric cell 300 which operates a timing device and subsequently the unique reciprocatory stacking mechanism of the stacker 31, as will be described with greater particularity hereinafter.

The novel reciprocatory stacker 31 receives the exposed plates 18 and stacks said plates in the tray 32. The plates 18 are stacked in a manner such that there is no sliding movement between the plates whereby the sharp edges, inherently present in the thin aluminum plates, will not scratch and deleteriously affect the previously exposed plates stacked in the tray 32. The stacker 31 comprises an upper frame portion generally designated 302 and a vertically positioned sub-frame 303.

Referring particularly to FIGURES 7 and 9, the upper frame 302 and the sub-frame 303 are mounted in a cantilever manner on the main support wall 33. The frame 302 comprises a main support plate 304 secured by weldments to a vertically disposed plate 306. A pair of gusset plates 307 and 308 are suitably positioned between the plates 304 and 306 to reinforce the main support plate 304 from the plate 306. The vertical plate 306 is secured to the main support wall 33 by adjustable fastening means 309 in a manner such that the plate 304 slopes downwardly from the front to the rear thereof. The fastening means 309 facilitate alignment of the stacking mechanism 31 with the support wall 33 and the endless web 120. Each fastening means 309 comprises a first bolt 310 which is center bored and threaded to receive therethrough a second bolt member 311. The bolt 310 is threaded through a suitable opening formed in the plate 306 and abuts the wall 33 at one end to position said plate from said Wall in the manner desired. A lock nut 312 threaded on the bolt 310 engages plate 306 retaining the bolt 310 in its desired position. Bolt 311, threaded through the 15 center bore of bolt 310, is turned into a threaded opening in the wall 33 thus securing the plate 306 and frame 302 thereto.

Extending upward from the main support plate 304 are transversely spaced side plates 313 and 314 which provide support for a plurality of transverse shafts as will hereinafter appear. Secured to the opposing surfaces of each of the side walls 313 and 314 are a pair of longitudinally disposed vertically spaced parallel members 315, 315a, 316 and 316a which form horizontal parallel tracks therebetween extending across each of said side plates substantially the entire length thereof. The tray 32 is disposed between the side plates 313 and 314 and is positioned on the upper surface of the main support plate 304. The tracks formed between the members 315, 315a and 316, 316a are disposed in a horizontal plane above a plane of the tray 32.

A pair of transversely disposed feed rollers 319 and 320 are supported by the rear portion of the side plates 313 and 314 to receive therebetween the plate 18 as it is directed across the shelf 301. Roller 319 is mounted on a shaft 321 which is fioatably supported in slotted openings 323 formed in the side walls 313 and 314. Roller 319 contacts and is driven by the roller 320 which is mounted on -a driven shaft 322. The driven shaft 322 is suitably journalled in the side plates 313 and 314 and extends through and is suitably journalled in the support wall 33. A sprocket wheel 325 is fixed to the extended end of shaft 322 and is driven from the main drive chain which passes around said sprocket wheel. The main drive chain drives the sprocket wheel 325, shaft 322 and the roller 320 in the direction indicated by the arrow 326 to feed the plate forwardly into the stacking mechanism. The feed roller 320 drives the plate at the same speed it is moved along the screen web 120.

As the plate 18 moves forwardly through the feed rollers 319 and 320, an extensible apron is moved forwardly in the plane of the tracks formed by the strip mem bers 315, 315a, 3 16 and 316a to receive said plate thereon. When the plate 13 drops from the rollers, it rests entirely on the apron which has been extended under the entire length of the plate. Means is then provided to retract the apron from beneath the plate allowing the same to be laid gently into the tray 32.

The apron as illustrated is formed of a pair of endless belts 373 and 374 directed around a plurality of transverse rollers, two of which are movable to move said apron from a retracted position adjacent one end of the tray 32 to an extended position overlying said tray. The first movable roller, formed by a shaft 339 and spaced rollers 340, is reciprocated across the tracks and the second movable roller, formed by a shaft 366 and a sleeve 370 moves in response to said reciprocation toward and away from one end of the tracks in a manner to be hereinafter described. The rotation of the belts 373 and 374 is limited to rotation in a single direction by a pair of shafts engaging each run of the belts between the shaft 339 and 366.

The first of these shafts limiting rotation is a transverse shaft 327 rotatably supported in the side plates 313 and 314 adjacent one end of the tracks formed by the members 315, 315a, 316 and 316a. A pair of spaced apart crowned rollers 328 are secured on the shaft 327 intermediate the ends thereof and a ratchet wheel 329 is $6- cured to said shaft on the outboard side of the plate 313. Positioned above the ratchet wheel 329 is a pivoted pawl 330 mounted on a pin 331. The pawl 330 is positioned and arranged to engage the teeth on the ratchet wheel 329 in the usual manner providing a one way braking device allowing only counterclockwise rotation of said ratchet wheel 329, shaft 327 and rollers 328 as viewed in FIG- URE 7. Positioned beneath and adjacent one end of the track formed by the members 315, 315a, 316 and 316a is a second shaft 332 limiting rotation of the belts 373 and 374. The shaft 332 is suitably journalled in the rear 16 portion of the plates 313 and 314; Shaft 332 carries a similar pair of crowned rollers 333 and has secured thereto a ratchet wheel 334. A pawl 335 is pivotally mounted on a pin 336 and engages the ratchet wheel 334 in a conventional manner to allow only clockwise rotation of the ratchet wheel 334, shaft 332 and rollers 333.

A pair of blocks 337 and 337a, preferably formed of a material such as nylon, are disposed between and slidable in the tracks formed by the members 315 and 315a on the side plate 313 and 316 and 316a on the side plate 314, respectively. The blocks 337 and 337a are formed with a center bore to receive the ends of the movable transverse shaft 339. The shaft 339 supports a pair of crowned rollers 340 and is moved forwardly and rearwardly across the tracks by a pair of oscillating crank arms 341 and 342. The crank arms 341 and 342 are formed with slotted openings 341a and 342a respectively, in the lower free ends thereof through which said shaft 339 extends. The arms 341 and 342 are secured to and extend radially from a shaft 344 journalled in the upper portion of the plates 313 and 314, as shown in the drawings. The shaft 344 has one end thereof extending through the main support wall 33 and has secured thereto a third crank arm 345. Oscillation of the shaft 344 and the arms 341 and 342 is provided by the crank arm 345 and a reciprocating slide block 346. The slide block 346 is movable longitudinally along a track formed adjacent the wall 33 by a pair of spaced apart parallel rails 347 and 343 secured to said wall 33. The slide block 346 is provided with a projection 346a in which is formed a threaded opening 34611. The block 346 is also provided with a cylindrical projection 3460 which extends into a slot 345a formed in the free end of the crank arm 345. A rotatable shaft 350 formed with helical screw threads 350a extends longitudinally parallel with the rails 347 and 343 and is threaded through the opening 346b to reciprocate the block 346 in the track formed by the rails 347 and 348. Rotation of the shaft 350 is effected by a suitable connection with a reversible direct current motor 351. The motor 351 is operated from a suitable source of direct current connected in circuit with a switching device controlled and operated by the aforementioned timer which is energized by the photoelectric cell 300 and said switching device is operated by a micro-switch (not shown) positioned at the forward end of the rails 347 and 343, and actuated by engagement of the slide block 346 therewith. Actuation of said micro-switch causes the switching device to reverse the motor 351 affording rearward movement of said block. Reciprocation of the block 346 causes oscillation of the arms 341 and 342 to move the shaft 339 and blocks 337 and 337a forwardly and rearwardly in the tracks formed in the side plates 313 and 314. Slots 304a and 304b, formed in the main support plate 304, allow unobstructed oscillation of the crank arms 341 and 342 as they carry the shaft 339 forwardly and rearwardly over the tray 32.

The lower sub-frame 303 comprises a pair of side plates 355 and 356 secured to the ends of transversely extending plate members 357 and 358. The frame 303 is supported from the wall 33 by means of bolts 359 and lock nuts 360. The bolts 359 extend through the plate 356 and are threaded into suitable openings provided in said wall 33. The lock nuts 360 serve to maintain the sub-frame 303 in proper aligned position. Secured adjacent the ends of the plates 357 and 358 are a pair of rails 361 and 362 which extend vertically and parallel with the side plates 355 and 356. The rails 361 and 362 have teeth 363 formed on the rear edges thereof forming cog rails. A second set of rails 364' and 365 are secured along the rear ends of the side plates 355 and 356. As shown in FIGURE 8, the rails 364 and 365 are formed of angle bars forming a forwardly projecting shoulder portion and a flat rolling surface.

The second movable shaft 366 is disposed transversely between the vertical side plates 35S and 356 and carries adjacent each end thereof a smooth roller 367, rotatably supported thereon, and a pinion 368 fixedly secured thereto. The rollers 367 are positioned adjacent the ends of the shaft 366 to roll up and down the rolling surface of the rails 364 and 365. The pinions 368 are positioned adjacent the rails 361 and 362 such that the teeth formed thereon intermesh with the teeth 363 formed on said rails 361 and 362. With the shaft 366 mounted in this manner, it can travel up and down the rails and will remain horizontal at all times. A sleeve 370 formed of a heavy material is journalled, by means of bearings 371 (see FIG- URE 8), intermediate the ends of the shaft 366, and is provided with spaced grooves 372 in the outer surface thereof.

A pair of endless flexible belts 373 and 374 pass around the crowned rollers 328 on shaft 327, 340 on shaft 339, 333 on shaft 332, and around the sleeve 370 on shaft 366 in the grooves 372, as shown most clearly in FIG. 7. The belts 373 and 374 form the apron which receives the plate 18 as it is fed into the stacker 31. This is effected by movement of the shaft 339 and the belts 373 and 374 forwardly from a retracted position as shown in FIGURE 10. The crank arms 341 and 342 move the shaft 339 at a speed such that the linear velocity of the belts 373 and 374 between the rollers 328 and-340 match the speed of the plate 18 being fed through rollers 319 and 320.

As the shaft 339 is moved forwardly, the belt is drawn around the shaft 327, causing the shaft 366 to move upwardly. FIGURE 11 shows the position of the apron after it has traveled substantially half way across the tracks formed for the shaft 339. This figure also shows the shaft 366 climbing racks 361 and 362 of the lower frame 303. As the shaft 339 reaches the forward end of the track, the plate 18 drops from the feed rollers 319 and 320 onto the belt, as shown in FIGURE 12. When the shaft 339 and the belt is in this extended position overlying the tray 32, the shaft 366 has climbed to the upper portion of the sub-frame 303. At this point the slide block 346 strikes the micro-switch (not shown), reversing the current to the motor 351 to effect rearward movement of said block and the shaft 339.

Upon rearward movement of the shaft 339, the belt is retracted from beneath the plate 18. Retraction of the belt is effected by the heavy sleeve 370 on shaft 366 tending to drop the shaft to its position in the lower portion of the sub-frame 303 under forces of gravity. Upon retraction of the belts from beneath the plate 18, shaft 327 is locked and shaft 332 is permitted to rotate in a clockwise direction to peel the belt from beneath the plate without imparting any rearward movement of the plate relative to the tray 32 since the direction of rotation of the belts is still in the same direction. As the belts are retracted, the plate 18 then is laid in the tray 32 as shown in FIGURE 13 and the air cushion formed between said plate and the tray 32, or previously stacked plates 18; lays the plate gently onto said plates or tray.

When the plate 18 is stacked in the tray, the belts 373 and 374 are in the retracted initial position such that subsequent plates which are fed across the shelf 301 are detected by the photoelectric cell 300 to again operate the stacking mechanism.

In the embodiment of the apparatus shown, the printing roll 48, drum 97 and drum 122, around which the plate 18 is directed, have a diameter approximating that of a conventional press, for example between eight and eight and one-half inches, such that the plates as they are conveyed therearound do not become folded to the extent that they retain a curved configuration and will not lay flat on the belt 110 and on the Fourdrinier screen web 120.

The main drive chain and the numerous conduits carrying the air under sub-atmospheric pressure, water and electrical leads for the circuit are disposed behind the main longitudinally extending support wall 33 as viewed in FIGURES 1A and 1B for several obvious reasons. Such reasons include the advantage of accessibility for re- 18 pair, the separation of the lubricated driven parts from the water sprays and vapor present in the plate processing areas, and the separation of the electromechanical mechanisms from the same sprays and vapor.

While one embodiment of the present invention has been described in the foregoing specification and illustrated in the accompanying drawings in connection with one specific purpose, it will be apparent that various omissions and substitutions and changes in the form and details of the machine illustrated, and its operation, may be made by those skilled in the art without departing from the spirit and scope of the invention. It is not intended, therefore, that the present invention shall be limited to the embodiment shown nor otherwise than by the terms of the appended claims.

What is claimed is:

1. An apparatus for successively exposing and processing presensitized planographic printing plates to prepare the same for use on a press comprising the combination of, exposure means for exposing a presensitized plate to actinic radiation through a negative transparency while maintaining said plate and transparency under intimate pressure-contact during said exposure and including means for transporting a said plate and transparency through said exposure means and to a separating unit, means defining a separating unit for separating an exposed plate and transparency, means for receiving the separated transparency, conveying means for advancing the exposed plate from said means defining said separating unit and along a predetermined path, and a series of processing stations arranged in closely adjacent successive order along said predetermined path for completing the preparation of the plate for press use and comprising: a coating station having a mechanism for applying a coating of treating solution to the exposed surface of the plate, a scrubbing station having a mechanism for scrubbing the surface of the plate with the treating solution as the plate is conveyed along said path, a cleaning station having a rinse applying and waste removing mechanism for cleaning the scrubbed surface of the plate, and receptor means for receiving the cleaned plates from said conveying means at the end of said predetermined path.

2. In an apparatus for exposing and developing printing plates having at least one surfacecoated with lightsensitive organic material the combination of: an exposure unit including a source of actinic radiation and means for advancing a composite formed of a sensitized plate member and a negative transparency disposed in close contact with a coated surface of said plate member through said exposure unit; means for separating the members of said composite after exposure and for directing the transparency to a receiving means therefor and directing the plate member to a conveying means for advancing the exposed plate along a predetermined path; coating means disposed adjacent said predetermined path and adapted to apply a uniform coating of treating solution onto the exposed surface as said plate member is conveyed along said path; scrubbing means disposed adjacent said predetermined path and adapted to scrub the surface of the plate coated with said treating solution as said plate is conveyed along said path; means adjacent said path for washing and wiping the scrubbed side of a plate as it is conveyed along said path to remove the unexposed sensitive coating and treating solution; means adjacent said path for drying the washed and wiped plate as it is conveyed along said path; and means at the end of said predetermined path for stacking the dried plates.

3. An apparatus for exposing and processing printing plates having at least one surface coated with diazo lightsensitive resin to prepare the same for use on a press comprising, in combination, an exposure unit including a revolvable transparent cylinder, a light source positioned within said cylinder, and continuous belt means snugly engaging the peripheral surface of said cylinder along a major portion of the length thereof affording rotation of said cylinder and advancement of a composite formed of a sensitized printing plate and a negative transparency disposed in close contact with the sensitized surface of said plate through said exposure unit to expose the light sensitive coating, means for separating the composite and directing the negative to a first receiving bin, means for placing the exposed plate on an endless con veyor, said endless conveyor being carried by a series of drums defining a predetermined path along which the exposed plate is conveyed, a series of stations arranged in successive order along said predetermined path, said stations comprising; a coating station including means for applying a coating of treating solution to the exposed surface of a plate which dissolves the unreacted lightsensitive coating, said means comprising a fountain roller and a coating roll movable into and out of coating position; a scrubbing station including means for mechanically scrubbing the coated surface of the plate While the treating solution is moist, said means including a scrubbing member with a pile surface engageable with the plate and driving means for moving said scrubbing member bidirectionally with respect to the surface of the plate as the same is conveyed through said scrubbing station; a washing station including mechanism for directing wash liquid onto the scrubbed surface of the plate and wiping the liquid and waste coating therefrom; a drying station including a hood positioned adjacent said conveyor through which hot air is directed toward said conveyor and the washed plate sufiicient to dry the plate; and a stacking mechanism positioned at the end of the said predetermined path for receiving the dried plates from said conveyor and placing them in a stack.

4. An apparatus for successively exposing and processing flexible presensitized planographic plates to prepare the same for use on a press comprising the combination of; an exposure unit including a revolvable radiant energy transmissive drum, a source of actinic radiation disposed within said drurn adjacent one longitudinal surface portion of said drum defining a treatment zone, and pressure transport means for advancing a composite formed of a sensitized printing plate and a negative transparency disposed in intimate contact with said plate through said treatment zone to impart a latent image on said plate; means for separating the transparency and plate and for directing the transparency to a receiving bin; a conveying means for advancing the separated plate along a predetermined path, said conveying means comprising an endless Fourdrinier-type screen web directed around a plurality of rotatable drums defining two straight line conveying runs, means positioned adjacent one of said runs for creating a subatmospheric pressure adjacent the web to draw a plate against said Web in transporting relation, and power transmitting means for driving said Web around said drums to convey a plate along the path defined by said runs; and a series of processing stations arranged in successive order along one of said straight line conveying runs for completing the preparation of the plate for press use and comprising a coating station having a mechanism for applying a coating of a treating solution to the latent image on a plate as the plate passes through the said coating station; a scrubbing station having a mechanism for scrubbing the surface of the plate coated with said solution while the same is still moist, and a cleaning station having a rinse applying and waste removing mechanism for cleaning the scrubbed surface of the plate; and receptor means positioned adjacent the end of one straight line conveying run for receiving the cleaned plates from said conveying Web.

5. An apparatus for exposing and developing presensitized printing plates comprising in combination, a cylinder over which exposure of the presensitized printing plate in contact with a printed negative is effected, a light source and reflector positioned adjacent a peripheral surface of said cylinder to define an exposure area, belt means for advancing a plate and negative around said cylinder and past said exposure area, means for separating the plate and negative after exposure of said plate is effected, said separating means comprising a pair of parallel rollers mounted transversely to the said belt means, said rollers having different diameters and being driven by means affording rotation of said rolls in a different direction with respect to each other and at a different speed with respect to each other at the nip area between said rollers, means directing the separated negative toward a receiving bin, means for receiving the separated plate and conveying the same along a predetermined path, coating means adjacent said predetermined path for applying a coating solution uniformly onto the exposed surface of the plate as said plate is conveyed along said path, means adjacent said predetermined path for scrubbing said coated surface of a plate with a uniform scrubbing motion and for washing and wiping the scrubbed surface of a plate, and a tray disposed at the end of said predetermined path to receive the exposed and processed plates.

6. A pressure transport apparatus suitable for advancing flexible sheet materials in intimate pressure contact past a treatment zone comprising, a rotatably supported elongate drum, at least a pair of guide rolls positioned in spaced relation adjacent the periphery of said drum defining a treatment zone around a portion of said periphery therebetween, a plurality of steering roll assemblies each having at least two rolls rotatably supported on axes substantially perpendicular to a plane tangential to the surface of a pair of said guide rolls, a single endless flexible belt having a width substantially less than the length of said drum passing around one of said guide rolls, around said drum through said treatment zone, around another of said guide rolls and around the rolls of one of said steering roll assemblies, then back around said one of said guide rolls, through said treatment zone, around another of said guide rolls to the next adjacent steering roll assembly and back around the guide rolls and drum affording a plurality of simultaneous sidebyside convolutions in said belt around said guide rolls and said drum to cover a major portion of the length of the latter, and spaced end steering roll assemblies affording means for directing said belt back across the drum in a direct path from adjacent one end of said drum to a position adjacent the other end thereof, and means for transmitting power to said belt affording movement of the same and rotation of said drum.

7. A pressure transport apparatus as described in claim wherein means are provided for placing said belt under tension to tightly press each convolution thereof against; said drum.

8. A device for exposing presensitized printing plates comprising in combination, a revolvable transparent print ing cylinder around which a printing plate and a printed negative in contact with the sensitized surface of said printing plate may be conveyed, a source of actinic light disposed within said cylinder, a shield within said cylinder positioned with respect to said source of light to define an exposure area along the length of said cylinder, a single endless flexible conveyor belt directed over a plurality of rollers positioned in adjacent parallel relation with respect to said cylinder, said belt having a width substantially less than the length of said cylinder, steering means for directing said belt around said rollers and said cylinder such that said belt makes a plurality of simultaneous side-by-side convolutions about the periphery of said cylinder and back across said cylinder from a posi tion adjacent one end thereof to a position adjacent the: other end thereof to form an endless path for said belt such that the same will cover a substantial portion of the length of said cylinder, said simultaneous convolutions: of said belt applying rotary motion to said cylinder to convey a plate member and a printed negative in intimate; contact therewith through said exposure area, and meansv for driving said belt around said rollers and steering means.

9. A pressure transport apparatus suitable for advancing flexible sheet materials in intimate pressure contact through a treatment zone comprising: a main drum having a portion of its periphery disposed in a treatment zone; a pair of rollers mounted parallel with the axis of said drum and providing a first belt-reversing face adjacent one side of said treatment zone and a second belt-reversing face adjacent the other side of said treatment zone respectively; a second pair of rollers mounted parallel with respect to said drum and said first mentioned pair of rollers and mounted in spaced relation to said main drum periphery on the same side of the drum axis as said treatment zone to afford a first and second belt-directing face; a plurality of steering rolls in paired relation positioned between said second pair of rollers and having their axis substantially perpendicular to the common plane joining said belt-directing faces of said second pair of rollers and the rolls of each pair having an axially offset arrangement with relation to said drum; a pair of pulleys positioned parallel and rearwardly of said second pair of rollers with one of said pulleys adjacent each of said second pair of rollers and said pulleys being at opposite ends of said drum; additional roll means positioned adjacent each of said second pair of rollers in axially aligned relation with said pulleys with their axes substantially perpendicular to the axes of said pulleys; and a single narrow endless belt interconnecting said rollers, rolls, pulleys, and roll means and passing in at least one advancing cycle around said first belt-reversing face, around at least a portion of said drum positioned in said treatment zone, around said second beltreversing face, around the first said belt-directing face, around a pair of said plurality of steering rolls, around said second belt-directing face, and thence back to and around said first belt-reversing face in a position axially offset with respect to the first path around said first beltreversing face; and from the final of said advance cycles passing in a return cycle around said first belt-reversing face, around said portion of said drum in said treatment zone, around said second belt-reversing face to one of said pulleys, to one of said roll means, across to the other 22 of said pulleys, and around the other of said roll means from a position adjacent one end portion of said drum to a position adjacent the other end portion of said drum; and means for transmitting power to said belt affording movement thereof around said rollers, rolls, pulleys and roll means.

10. A device for exposing presensitized printing plates comprising in combination, a revolvable transparent cylinder around which a printing plate and a printed transparency in contact with the sensitized surface of said printing plate may be conveyed, a source of actinic light disposed within said cylinder, shield means mounted within said cylinder and positioned to direct said light toward a predetermined surface area of said cylinder to define an exposure area, a single endless flexible conveyor belt having a width substantially less than the length of said cylinder, means directing said belt around a predetermined arcuate portion of said cylinder through said exposure area in adjacent axially spaced paths such that said belt makes a plurality of convolutions about the predetermined surface of said cylinder and is directed back across said cylinder from one end thereof to a position adjacent the other end thereof defining an endless path for said belt, and means imparting linear movement to said belt to move the same along said path such that said belt and cylinder will convey a plate member and a said printed negative in intimate contact through said exposure area.

References Cited by the Examiner UNITED STATES PATENTS 1,715,301 5/1929 Mason et al.

1,811,618 6/1931 Dudley 27l-68 1,836,856 12/1931 Lloyd 27168 2,355,109 8/1944 Riddick -94 2,774,290 12/1956 Mormann 9577.5 2,913,974 11/1959 Sabel et al. 95-94 3,022,716 2/1962 Smith et al. 9577.5 3,104,602 9/1963 Hersh 9577.5

EVON C. BLUNK, Primary Examiner. 

1. AN APPARATUS FOR SUCCESSIVELY EXPOSING AND PROCESSING PRESENSITIZED PLANOGRAPHIC PRINTING PLATES TO PREPARE THE SAME FOR USE ON A PRESS COMPRISING THE COMBINATION OF, EXPOSURE MEANS FOR EXPOSING A PRESENSITIZED PLATE TO ACTINIC RADIATION THROUGH A NEGATIVE TRANSPARENCY WHILE MAINTAINING SAID PLATE AND TRANSPARENCY UNDER INTIMATE PRESSURE-CONTACT DURING SAID EXPOSURE AND INCLUDING MEANS FOR TRANSPORTING A SAID PLATE AND TRANSPARENCY THROUGH SAID EXPOSURE MEANS AND TO A SEPARATING UNIT, MEANS DEFINING A SEPARATING UNIT FOR SEPARATING AN EXPOSED PLATE AND TRANSPARANCY, MEANS FOR RECEIVING THE SEPARATED TRANSPARENCY, CONVEYING MEANS FOR ADVANCING THE EXPOSED PLATE FROM SAID MEANS DEFINING SAID SEPARATING UNIT AND ALONG A PREDETERMINED PATH, AND A SERIES OF PROCESSING STATIONS ARRANGED IN CLOSELY ADJACENT SUCCESSIVE ORDER ALONG SAID PREDETERMINED PATH FOR COMPLETING THE PREPARATION OF THE PLATE FOR PRESS USE AND COMPRISING: A COATING STATION HAVING A MECHANISM FOR APPLYING A COATING OF TREATING SOLUTION TO THE EXPOSED SURFACE OF THE PLATE, A SCRUBBING STATION HAVING A MECHANISM FOR SCRUBBING THE SURFACE OF THE PLATE WITH THE TREATING SOLUTION AS THE PLATE IS CONVEYED ALONG SAID PATH, A CLEANING STATION HAVING A RINSE APPLYING AND WASTE REMOVING MECHANISM FOR CLEANING THE SCRUBBED SURFACE OF THE PLATE, AND RECEPTOR MEANS FOR RECEIVING THE CLEANED PLATES FROM SAID CONVEYING MEANS AT THE END OF SAID PREDETERMINED PATH. 